NATURAL CIRCULATION TYPE SODIUM-SULFUR BATTERY

PURPOSE:To achieve supply of sulfur smoothly at the time of discharge, increase the reaction electrode area at the time of discharge, and improve the energy efficiency by providing a sulfur-affinitive electron conductive material tightly attached to a sodium polysulfide-affinitive electron conductive material. CONSTITUTION:A stabilizing tube 11 is provided inside a solid electrolyte 2, sodium 5 is filled, a sodium polysulfide-affinitive electron conductive material 12 is mounted on the outer surface of the electrolyte 2, and a sulfur-affinitive electron conductive material 13 of felt of graphite is mounted on the outer surface of the conductive material 12. For a discharge reaction, the conductive material 13 absorbs sulfur exsisting in contact with its outer circumference, discharges it in the transmitting material 13, and generates sodium polysulfide. Sodium polysulfide gets into the conductive material 12 tightly attached to the conductive material 13, and gets down to the bottom of a battery container by the gravity. As discharge goes on, the quantity of sulfur is reduced to eliminate existence of sulfur 15 only on the battery container 1, while sulfur is supplied to the conductive material 13 by capillary phenomenon of the conductive material 13.